Trump accuses fired FBI chief James Comey of being swayed on Hillary Clinton email investigation by polls showing she was going to win

President brands ex-intelligence chief a 'slimeball' who 'wanted a job' in Democratic candidate's administration

Donald Trump has hit out at former FBI director James Comey on Twitter (Getty)

Donald Trump has claimed former FBI director James Comey was swayed in his investigation of Hillary Clinton’s private email server by polls showing she was on course to take the White House.

The US president took aim at Mr Comey in a string of tweets on Sunday, branding him a “slimeball” who “wanted a job” in a potential Clinton administration.

Mr Trump added the former intelligence chief “will go down as the worst FBI director in history” and should be jailed over details revealed in his new book, A Higher Loyalty: Truth, Lies and Leadership, which chronicles his experiences working with the president.

He also refuted a claim made in the book that he had asked Mr Comey to take a personal pledge of loyalty, dismissing it as “just another of his many lies”.

Mr Comey, who was fired by Mr Trump in May 2017, said in a clip released of an interview with ABC News he had assumed Ms Clinton would win the election.

He explained that this contributed to his decision to reopen the enquiry into the email controversy in October 2016, a matter of days before America went to the polls to choose its next president.

“I don’t remember consciously thinking about that, but it must have been because I was operating in a world where Hillary Clinton was going to beat Donald Trump, and so I’m sure that it was a factor,” he told the US broadcaster.

“I don’t remember spelling it out, but it had to have been, that she’s going to be elected president and if I hide this from the American people, she’ll be illegitimate the moment she’s elected, the moment this comes out.”

The full interview is due to air on Sunday.

The scandal revolved around Ms Clinton’s use of a private email server for official correspondence while serving as secretary of state under then-President Barack Obama.

Some of the messages were later determined to contain classified information.

However, the FBI probe concluded no criminal charges should be brought against Ms Clinton over her use of private servers.

The Democratic Party candidate later attributed her loss to Mr Trump in the 2016 election to the investigation, claiming it killed the “momentum” of her campaign.

Mr Comey’s book has attracted the ire of Mr Trump ahead of its release, leading him to call Mr Comey a “proven leaker and liar” and an “untruthful slime ball” as the first extracts emerged.

The memoir describes the president as shorter than the six-foot-eight Mr Comey had expected, with “bright white half-moons” under his eyes attributed to the use of tanning goggles.

Mr Comey also claims Mr Trump was obsessed with the infamous dossier compiled by former British spy Christopher Steele, which contained accusations the president watched two prostitutes urinate on a bed in a Moscow hotel room.

According to the book, Mr Trump tried to convince Mr Comey the story was untrue by saying he was a “germaphobe”.